Reactions of halodeoxycelluloses with inorganic nucleophiles in aprotic amide solvents

Abstract

Chloro- and bromodeoxycelluloses with high degrees of halogen substitution were treated with inorganic halides, thiocyanate and cyanide in N,N-dimethylace tamide or N, N-dimethylformamide. The reaction systems were homogeneous in most cases. The products were hydrolyzed and the resulting saccharides were analyzed by gas chromatography and gas chromatography-mass spectrometry as their trifluoroacetyl derivatives. The reactivity of halide ions in nucleophilic substitution increased in the order I- Br- Cl, which agrees with the order of nucleophilicity of unsolvated halide ions in aprotic organic solvents. The reaction of halodeoxycelluloses with KSCN yielded thiocyanatodeoxycelluloses with more than 90% conversion at 150. in 2 h. The reaction of bromodeoxycellulose with KCN at 100. for 2 h did not give cyanodeoxycellulose, and most of the 6-bromo-6-deoxyglucose units were converted into 3,6- anhydroglucose units. © 1992, The Society of Fiber Science and Technology, Japan. All rights reserved.